Blood on a pair of sneakers belonging to a woman who killed herself last week after being questioned by police about a murder in Imabari, Ehime Prefecture, has DNA that matches that of the victim, investigative sources said Monday.
The sources also said that blood stains found at a different residence where 81-year-old Satsuki Ochi was found dead with stab wounds on April 26 also matches the woman's DNA.
Police suspect that the woman, who is in her 30s and whose name is being withheld, was involved in both slayings. The case she was originally questioned about involved 92-year-old Yukie Okamoto, who was killed last Wednesday.
Knives that are believed to be the murder weapons were left in the victims' homes, which were only 400 meters apart.
Okamoto's son, Hisayuki, 70, who was severely wounded, told investigators he had been stabbed by an unknown woman.
The female suspect, who lived near Okamoto, underwent questioning on a voluntary basis last Thursday but was found dead the next morning, just before investigators planned to take her in for further questioning.
She left a suicide note in which she denied involvement in Okamoto's death, one of her family members said.